Vladimir Simic

Bee Colony Optimization Approach to Solving the Anticovering Location Problem

Bee colony optimization (BCO) is a relatively new metaheuristic designed to deal with hard combinatorial optimization problems. It belongs to the group of nature-inspired methods that explore collective intelligence applied by the honey bees during the nectar collecting process. In this paper, BCO is applied to the anticovering location problem (ACLP), one of the fundamental problems in the area of discrete location. Because a BCO algorithm has not been used in the literature related to the ACLP so far, it was a challenge to test its performances on this nondeterministic polynomial time (NP)-hard problem. The numerical experiments performed on the well known benchmark problems show that the proposed algorithm can generate high-quality solutions in reasonable CPU times.

Modelling production processes in a vehicle recycling plant

The European Directive on end-of-life vehicles (ELVs) fundamentally changed the business philosophy of the European vehicle recycling system, which was exclusively profit-oriented. As the dominant participants of this system, vehicle recycling plants (VRPs) are especially affected by its implementation. For VRPs to successfully respond to the prescribed eco-efficiency quotas, investment will be needed to procure modern sorting equipment as well as to achieve full transformation of their production process. However, before VRPs decide to make this very important investment decision, it is necessary to determine the adequacy of such a decision in detail. Consequently, the following questions become unavoidable: Can modernly equipped VRPs conduct profitable business? Are eco-efficiency quotas actually attainable? How will the new changes in vehicle design influence VRPs? To provide answers to these essential questions, a production planning model of a modernly equipped VRP was first developed and then tested extensively using real data. Based on the answers provided by the proposed model testing analysis it was concluded that VRP transformation is not only necessary but completely justified and that the final success of the ELV Directive is realistic.

Interval linear programming model for long-term planning of vehicle recycling in the Republic of Serbia under uncertainty

An interval linear programming approach is used to formulate and comprehensively test a model for optimal long-term planning of vehicle recycling in the Republic of Serbia. The proposed model is applied to a numerical case study: a 4-year planning horizon (2013–2016) is considered, three legislative cases and three scrap metal price trends are analysed, availability of final destinations for sorted waste flows is explored. Potential and applicability of the developed model are fully illustrated. Detailed insights on profitability and eco-efficiency of the projected contemporary equipped vehicle recycling factory are presented. The influences of the ordinance on the management of end-of-life vehicles in the Republic of Serbia on the vehicle hulks procuring, sorting generated material fractions, sorted waste allocation and sorted metals allocation decisions are thoroughly examined. The validity of the waste management strategy for the period 2010–2019 is tested. The formulated model can create optimal plans for procuring vehicle hulks, sorting generated material fractions, allocating sorted waste flows and allocating sorted metals. Obtained results are valuable for supporting the construction and/or modernisation process of a vehicle recycling system in the Republic of Serbia.

Interval-parameter chance-constraint programming model for end-of-life vehicles management under rigorous environmental regulations.

As the number of end-of-life vehicles (ELVs) is estimated to increase to 79.3 million units per year by 2020 (e.g., 40 million units were generated in 2010), there is strong motivation to effectively manage this fast-growing waste flow. Intensive work on management of ELVs is necessary in order to more successfully tackle this important environmental challenge. This paper proposes an interval-parameter chance-constraint programming model for end-of-life vehicles management under rigorous environmental regulations. The proposed model can incorporate various uncertainty information in the modeling process. The complex relationships between different ELV management sub-systems are successfully addressed. Particularly, the formulated model can help identify optimal patterns of procurement from multiple sources of ELV supply, production and inventory planning in multiple vehicle recycling factories, and allocation of sorted material flows to multiple final destinations under rigorous environmental regulations. A case study is conducted in order to demonstrate the potentials and applicability of the proposed model. Various constraint-violation probability levels are examined in detail. Influences of parameter uncertainty on model solutions are thoroughly investigated. Useful solutions for the management of ELVs are obtained under different probabilities of violating system constraints. The formulated model is able to tackle a hard, uncertainty existing ELV management problem. The presented model has advantages in providing bases for determining long-term ELV management plans with desired compromises between economic efficiency of vehicle recycling system and system-reliability considerations. The results are helpful for supporting generation and improvement of ELV management plans.

Karakterizacija zeolitskog tufa iz ležišta „Igroš-Vidojevići“ sa geološkog i tehnološkog aspekta

U radu su prikazani rezultati ispitivanja zeolitskog tufa iz ležista „Igros-Vidojevici“ u cilju sagledavanja mineragenetske karakteristike ležista, utvrđivanja kvaliteta zeolita, primene i nacina valorizacije. Iz tih razloga je uzet uzorak iz podine ležista „Zeolit 1“ i uzorci sredisnjeg dela ležista „Zeolit 2“, „Zeolit 3“, „Zeolit 4“ i „Zeolit 5“. U karakterizaciji uzoraka primenjene su sledece metode: elementna hemijska analiza, kvantitativna SEM/EDS analiza, određivanje koeficijenta adsorpcije metilen plavog i kapaciteta katjonske izmene (KKI), rendgenska difrakcija praha (RDP), termijska analiza (TG, DTA) i i nfracrvena spektroskopija sa Furijeovom transformacijom (FTIR). Rezultati rendgenske i termijske analize su pokazali da podinu ležista u najvecoj meri cini glina, dok je u ostataku ležista zeolit. Sa mineragenetskog aspekta zapaža se da se radi o zeolitu-klinoptilolitu koje je najvece u uzorcima „Zeolit 2“ i „Zeolit 3“, pa su oni i najkvalitetniji. Na to ukazuju i vrednosti njihovog KKI i to 141,99 mmol/100g odnosno 121,01 mmol/100g. Uzorci „Zeolit 4“ i „Zeolit 5“ imaju nesto manji KKI (89,48 mmol/100g i 83,75 mmol/100g), losijeg su kvaliteta. Rezultati rendgenske i termijske analize su pokazali da podinu ležista u najvecoj meri cini glina, dok je u ostataku ležista zeolit. Sa mineragenijskog aspekta se može reci da je prisustvo zeolitskih minerala hojlanditskog tipa najvece u uzorcima „Zeolit 2“ i „Zeolit 3“, pa su oni i najkvalitetniji. Na to ukazuju i visoke vrednosti njihovog KKI i to 141,99 meq/100g odnosno 121,01 meq/100g. Zbog toga bi ovi uzorci mogli imati prakticnu primenu kao adsorbenti neorganskih zagađivaca iz kontaminiranih voda, a zbog visokog sadržaja osnovnog zeolitskog minerala potencijalno se mogu koristiti i kao sredstvo za uklanjanje mikotoksina iz stocne hrane. Uzorci „Zeolit 4“ i „Zeolit 5“ imaju nesto niži KKI (89,48 meq/100g i 83,75 meq/100g), slabijeg su kvaliteta, pa se potencijalno mogu upotrebiti za poboljsanje kvaliteta zemljista.

Mineraloška i kristalohemijska svojstva minerala HEU-tipa iz ležišta zeolitskih tufova Srbije

The results of perennial research of several Serbian zeolitic tuffs enriched with HEU-type minerals are presented in this paper. There are several recognized zeolitic tuff deposits containing HEU-type minerals: Zlatokop, Igros, Beocin, Toponica, Slanci, but their comparative mineralogical and crystallochemical features have not been studied in detail so far. These zeolitic tuff deposits are spatially and genetically connected to volcanic and pyroclastic rocks of marine and lake environments of Senonian and Eocene, and Neogene age, respectively. As a result of devitrification and diagenesis process of volcanic glass within zeolitic tuffs hypocrystalline porphiry and vitroclastic textures occur. The studied zeolitic tuffs are mainly composed of heulandite occuring in a form of needle- to plate-like crystals of 0,1 do 100 μm in length, associated with other silicates. Depending on the type and content of exchangeable cations as well as the thermal stability of these raw materials, 24 clinoptilolite-Ca and heulandite-Ca can be distinguished. The values of cation exchange capacity and surface area capacity range from 96 to 166 meq/100 g, and from 8,0 to 10,5 meq/100 g, respectively. HEU-type minerals can be distinguished either by a Si/Al ratio or arrangement of extra framework cations within the crystal structure of these minerals. [Projekat Ministarstva nauke Republike Srbije, br. TR 34013: Osvajanje tehnoloskih postupaka dobijanja ekoloskih materijala na bazi nemetalicnih mineralnih sirovina i br. 45012: Sinteza, procesiranje i karakterizacija nano strukturnih materijala za primenu u oblasti energije, mehanickog inţenjerstva, zastite životne sredine i biomedicine]

Gemstone deposits of Serbia

Abstract Gemstone minerals in Serbia have never been regarded as an interesting and significant resource. Nevertheless, more than 150 deposits and occurrences have been recorded and some of them preliminarily explored in the last 50 years. The majority of deposits and occurrences are located within the Serbo-Macedonian metallogenic province and the most significant metallogenic units at the existing level of knowledge are the Fruska Gora ore district, Cer ore district, Sumadija metallogenic zone, Kopaonik metallogenic zone and Lece-Halkidiki metallogenic zone. The most important genetic type of deposits is hydrothermal, particularly in case of serpentinite/peridotite as host/parent rock. Placer deposits are also economically important. The dominant gemstones are silica minerals: chalcedony (Chrysoprase, carnelian, bluish chalcedony etc.), jasper (picture, landscape, red etc.), common opal (dendritic, green, milky white etc.), silica masses (undivided), and quartz (rock crystal, amethyst etc.). Beside silica minerals significant gemstones in Serbia include also beryl (aquamarine), garnet (almandine and pyrope), tourmaline, fluorite, rhodochrosite, carbonate-silica breccia, carbonate-silica onyx, silicified wood, howlite, serpentinite, marble onyx, and kyanite. This paper aims to present an overview of Serbian gemstone deposits and occurrences and their position based on a simplified gemstone metallogenic map of Serbia, as well as genetic-industrial classification of gemstone deposits and gemstone varieties.

Geochemical and Sedimentation History of Neogene Lacustrine Sediments from the Valjevo-Mionica Basin (Serbia)

Valjevo-Mionica Basin is one of the numerous lacustrine Neogene basins in Serbia. After Aleksinac Basin, according to the quality and amount of oil shale, it is one of the main deposits of this raw material in Serbia. The most important oil shale deposits in ValjevoMionica Basin are located in the central part of the basin (Bela stena series, Suseocka and Radobicka Bela Stena). The kerogen content in oil shales ranged from 8 16 %. The average oil yield of 6.3 % is of economical value.

Studying of liquid thermolysis products of various types of immature kerogen in sedimentary lacustrine rocks from the valjevo-Mionica basin, Serbia, and the effect of Pt4+ and Ru3+ ions on their yield and the hydrocarbon composition

Liquid thermolysis products of various types of immature kerogen from sedimentary lacustrine rocks from the Valjevo-Mionica basin in Serbia were studied to evaluate the generation potential of kerogen contained in the organic matter (OM) of the rocks, determine the composition of the biomarkers and alkylaromatics in the liquid thermolysis products, and elucidate the effect of Pt4+ and Ru3+ ions (which were added in the form of inorganic salts) on the yield and hydrocarbon composition of the liquid thermolysis products. For this purpose, representative bitumen-free samples A and B of the sedimentary rocks were subjected to thermolysis under various conditions. Rock A contains high amount of immature organic matter, which is dominated by kerogen type I/II and was generated under strongly reduced sedimentation conditions at a high salinity. Sample B is poorer in immature OM than sample A, and the OM of the former contains kerogen type II/III and was generated predominantly in a reduced environment. The content of the liquid products and the concentrations of hydrocarbons obtained in the course of thermolysis of bitumen-free sample A and the typical oil distribution of the biomarkers and alkylaromatics in the thermolysis products confirm a high generation potential of OM in this rock. In all of our experiments on the thermolysis of bitumen-free sample B, the yield of liquid products and hydrocarbons is low. According to the kerogen type, the thermolysis of this rock generates much gases. The Pt4+ and Ru3+ ions (added in the form of simple inorganic salts) increased the yield of liquid (kerogen type I/II) and gaseous (kerogen type II/III) products. During the thermolysis of various type of immature kerogen in the lacustrine sedimentary rocks at a temperature of 400°C, the OM attained maturation corresponding to the early catagenesis level. Saturated biomarkers and alkylaomatics in the thermolysis products of both samples display typical oil distributions. The type of the source OM most strongly affects the composition of n-alkanes and alkylnaphthalenes. The metal ions used in this research served as catalysts for the methylation process during the thermolysis of immature kerogen, regardless of its type. The effect of the Pt4+ and Ru3+ ions on other transformations of the hydrocarbons, for example, the destruction of high-molecular n-alkanes to low-molecular ones and on isomerization reactions in molecules of polycyclic biomarkers and alkylaromatics to thermodynamically more stable isomers in the thermolysis products is controlled, first of all, by the type of the source OM.